Effect of cooking oil on the characteristics and shelf life of shredded catfish (Clarias sp)

Abstract

The purpose of this research is to identify the characteristics of shredded catfish (Clarias sp) processed with and without cooking oil and determine the shelf life by using the Arrhenius method. The shredded catfish was made by filleting the fish and soaking in a 2% vinegar solution for 10 minutes, and boiling the fillets for 15 minutes in a 2% salt solution mixed with 2% bay leaves and 2% lemongrass with the ratio of fillet: solution (1:2 (w/v)). The cooked fillets were then pressed, shredded into small pieces, and added with spices (2% red onion, 3% garlic, 15% granulated sugar, 1% coriander, 1% galangal, and 0.5% flavoring powder) and 20% coconut milk, then cooked until it dried. The shredded catfish was observed for its proximate values, while the shelf life was determined using the acceleration method (Arrhenius) at three different storage temperatures and day of observation, i.e. at 25°C was for 0, 10, 20, 30, 40 days; at 35°C was for 0, 7, 14, 21, 28 days and at 45°C was for 0, 3, 6, 9, 12 days. The parameters of observation for shredded catfish's shelf life were peroxide value, Aw, total plate count (TPC), and sensory test (hedonic). The result of proximate value showed that the protein content of shredded catfish with oil was lower than without oil, while moisture content was higher for treatment using oil. The shelf life of shredded catfish with cooking oil was shorter than without cooking oil, estimated for 83 days at 25°C, 55 days at 35°C, 47 days at 45°C, compared to 155 days at 25°C, 103 days at 35°C, and 62 days at 45°C, respectively. This was supported by the panelist's preferences for shredded catfish without oil at the end of the observation. These results indicate that the use of cooking oil during the cooking process of shredded catfish greatly affects the product's shelf life.